The PrepareForUpdateStateMachineType may be used if the device requires to be prepared before the update. Another option is to delay the resuming of normal operation until all update actions are executed. This supports to prepare for update option of 8.3.4.2.

If a Server implements this state machine, a Client shall use it except if the UpdateBehavior indicates that this is not necessary for the transferred software. If preparation is required, the installation is only allowed if the PrepareForUpdateStateMachine is in the PreparedForUpdate state.

The state machine is illustrated in Figure 47, Figure 48 and formally defined in Table 74. The transitions are formally defined in Table 76.

Figure 47 – PrepareForUpdate state machine

Figure 48 – PrepareForUpdateStateMachineType

Table 74 – PrepareForUpdateStateMachineType definition

Attribute	Value
BrowseName	PrepareForUpdateStateMachineType
IsAbstract	False
References	NodeClass	BrowseName	DataType	TypeDefinition	ModellingRule
Subtype of the FiniteStateMachineType defined in OPC 10000-5.
HasComponent	Variable	PercentComplete	Byte	BaseDataVariableType	Optional
HasComponent	Method	Prepare			Mandatory
HasComponent	Method	Abort			Mandatory
HasComponent	Method	Resume			Optional
HasComponent	Object	Idle		InitialStateType
HasComponent	Object	Preparing		StateType
HasComponent	Object	PreparedForUpdate		StateType
HasComponent	Object	Resuming		StateType
HasComponent	Object	IdleToPreparing		TransitionType
HasComponent	Object	PreparingToIdle		TransitionType
HasComponent	Object	PreparingToPreparedForUpdate		TransitionType
HasComponent	Object	PreparedForUpdateToResuming		TransitionType
HasComponent	Object	ResumingToIdle		TransitionType
Conformance Units
DI SU PrepareForUpdate

The component Variables of the PrepareForUpdateStateMachineType have additional Attributes defined in Table 75.

Table 75 – PrepareForUpdateStateMachineType Attribute values for child Nodes

BrowsePath	Value Attribute
Idle 0:StateNumber	1
Preparing 0:StateNumber	2
PreparedForUpdate 0:StateNumber	3
Resuming 0:StateNumber	4
IdleToPreparing 0:TransitionNumber	12
PreparingToIdle 0:TransitionNumber	21
PreparingToPreparedForUpdate 0:TransitionNumber	23
PreparedForUpdateToResuming 0:TransitionNumber	34
ResumingToIdle 0:TransitionNumber	41

Table 76 – PrepareForUpdateStateMachineType Additional References

SourceBrowsePath	Reference Type	Is Forward	TargetBrowsePath
Transitions
IdleToPreparing	FromState	True	Idle
	ToState	True	Preparing
	HasEffect	True	TransitionEventType
PreparingToIdle	FromState	True	Preparing
	ToState	True	Idle
	HasEffect	True	TransitionEventType
PreparingToPreparedForUpdate	FromState	True	Preparing
	ToState	True	PreparedForUpdate
	HasEffect	True	TransitionEventType
PreparedForUpdateToResuming	FromState	True	PreparedForUpdate
	ToState	True	Resuming
	HasEffect	True	TransitionEventType
ResumingToIdle	FromState	True	Resuming
	ToState	True	Idle
	HasEffect	True	TransitionEventType

This percentage is a number between 0 and 100 that informs about the progress in the Preparing or the Resuming States. It may be used whenever the activity takes longer and the user should be informed about the completion. If the state machine is in Idle or PreparedForUpdate State it shall have the value 0.

Note: This information is for the user only. It shall not be used to detect completion of the transition.

The Prepare Method may be called to prepare a device for an update. This call transitions the device into the state Preparing.

After the preparation is complete the state machine may perform an automatic transition to the state PreparedForUpdate.

If the preparation cannot complete and the device does not get prepared for update the state machine transitions back to Idle. In this case a message with the reason should be provided to the user via the UpdateStatus.

Signature

Prepare();

Method Result Codes (defined in Call Service)

Result Code	Description
Bad_InvalidState	If the PrepareForUpdateStateMachineType is not in Idle state.

If the preparation takes too long or does not complete at all because the required internal conditions are not met the Abort Method may be called to abort the preparation. This call transitions the device back to the Idle state.

Note: If the transition from Preparing to Idle cannot complete instantly a Client needs to subscribe for the events or the state variable of the PrepareForUpdateStateMachine.

Signature

Abort();

Method Result Codes (defined in Call Service)

Result Code	Description
Bad_InvalidState	If the PrepareForUpdateStateMachineType is not in Preparing state.

A call to the optional Resume Method transitions the device into the state Resuming. After the resuming is complete the state machine performs an automatic transition to the Idle state. If the method is not supported, the transitions to Resuming and back to Idle shall be done by the Server automatically. If the method is supported, there shall not be an automatic transition to Resuming. Supporting this method enables the Client to group several activities like backup, install, restore on a single device or group the update of multiple devices before the devices are allowed to Resume their operation again.

Signature

Resume();

Method Result Codes (defined in Call Service)

Result Code	Description
Bad_InvalidState	If the PrepareForUpdateStateMachineType is not in PreparedForUpdate state or if the InstallationStateMachine is still in the state Installing.